Here is section “I” of the current version of FDA’s Acidified Process Filing form 2541e.  Here are some hints for completing the form when using a hot fill hold (HFH) process.

  • First, note the blacked out portions.  Nothing needs to be entered in these areas.
  • Column 1 is 01 for your first filing (of the form).
  • Column 2 is 01 for the first step (in this one step process)
  • Column 3 – check the box “Lowest Hold temp.” and below the word Fahrenheit write in the temperature provided by your process authority.  A standardized default value often used is 180F.
  • Column 4 – is the amount of time the HFH food must stay at the temperature indicated in Column 3.  This is usually minutes, so check the box “minutes”.  If the process authority said to invert food container and hold 1 minute; then right-side-up and hold 1 minute (the total time equals 2 minutes).  Write in 2.00 in the box below “minutes”.
  • Column 6 captures the scientific data that the process authority (PA) provides.  It is best not confuse this with processing time and temperature.  Just enter the data.  In almost all cases the “Other F” box is checked.  Write in the values provided by your PA for Ref T, Z, and below that: minutes (t).
  • Lastly, Column 11 is for Other factors.  If the processing time and temperature provided by your PA is valid only for a specific pH range, it will be indicated here.

Traditional tempeh is made from mold fermented soybeans. Whole soybeans are soaked, dehulled, cooked, cooled, and fermented. Specialty tempeh may include other sources of starches such as beans or whole grains.

From a food safety perspective,
tempeh is analogous to the hazards of sushi rice.

Sushi rice is soaked and cooked with the intention of warm holding for an extended period. Tempeh is soaked and cooked with the intention of fermenting at 30C for 24-48 hours. In both, the cooking process eliminates vegetative pathogens. This leaves the three spore-forming pathogens as hazards.

Spore forming pathogen Possible Control Measures
C. botulinum pH ≤ 4.6; presence of oxygen, competitive microbial cultures
C. perfringens pH ≤ 5.3; presence of oxygen, competitive microbial cultures
B. cereus pH ≤ 4.3; competitive microbial cultures

Tempeh soybeans, beans, or grains are soaked to hydrate them from their dried state. Hydrating these starches also hydrates the bacterial and mold spores present. Therefore, it is safest to hydrate at refrigeration temperature. Alternatively, the soaking water can be acidified to pH ≤ 4.3 by adding a mild acidulant such as vinegar, lactic acid, or acetic acid. High acid levels inhibit the three spore-forming pathogens. Later, during fermentation high acid levels will favor mold growth over growth of spoilage microorganisms. This acidulation step is not traditional but is analogous to food safety changes made to traditional preparations of sushi rice.

Once hydrated and dehulled, the starches are cooked. As noted above, cooking eliminates all of the vegetative pathogens, leaving just the three spore-forming pathogens a concern.

After cooking, the dehulled soybeans are spread thin to cool. Spreading the starches thinly exposes all of the surfaces to air. Oxygen will prevent Clostridium growth and may lead to lethality. It is noted that there will likely be anaerobic areas. Bacillus cereus is facultative. Acidulated starches will prevent growth of the spore-forming pathogens regardless of the presence or absence of oxygen.  If starches are not acidulated to pH ≤ 4.3, then rapid cooling is required (130-70F in ≤ 2h) to prevent spore-forming pathogen outgrowth and possible toxin formation.

Historically, the competitive microbial culture in tempeh was a Rhizpus (R. oryzae or R. oligosporus) usually originating from a banana or plant leaf the cooked soybeans were wrapped in. Today, a tempeh culture can easily be purchased. Starter spores are sprinkled onto the surface. The tempeh is allowed to ferment at about 30C for 24-48 hours. If using a quality starter culture, the mold will grow rapidly in ≤ 4h (functioning as a competitive antimicrobial culture). After 24-48h the tempeh will be held together by white mold mycelium indicating a successful ferment.

from wikimedia white mycelium with black sporangiospores

After 48h the tempeh culture may sporulate producing dark or black spores. This is not harmful, but is considered a quality defect. Likewise, fermenting past 48h may develop ammonia byproducts reducing quality and increasing the pH. An increase in pH is less of a concern to food safety at this point, since an active (competitive inhibitory) mold culture is present.

Tempeh is best stored frozen.  If kept refrigerated it will over-ripen in about 2-3 days (black spores and ammonia).   If left at ambient temperature it will over-ripen in 12-24h.  An additional food safety hurdle is that most tempeh is fried or deep-fried.

For some additional details on Tempeh consult The Book of Tempeh (Wm Shurtleff).

Many food processors ask how long can they leave RTE foods out of cold holding to perform further preparations or packaging?

Here is the answer from FDA.  Note that column 2 says “internal temperature” and not ambient (processing room) temperature.

I made what I think is a correction to the FDA data on Raw > 50F (2nd row).  The original FDA reference lists > 70F.  That seems to be an error to me.  I sent a FDA TAN request to see what FDA thinks.

Here is the standard validation support for a USDA food (and HACCP plan).  Be sure and cite this Tomkin paper and place a copy in your HACCP validation file (required by USDA FSIS).

Download (PDF, 137KB)

Issue 1: Cook-Chill or Sous Vide 3-502.12 (D)(2)

(f) Held in a refrigeration unit that is equipped with an electronic system that continuously monitors time and temperature and is visually examined for proper operation twice daily, with a verifiable electronic monitoring device to ensure that times and temperatures are monitored Pf

(g) If transported off-site to a satellite location of the same business entity, equipped with verifiable electronic monitoring devices to ensure that times and temperatures are monitored during transportation, Pf and

Cook chill (sous vide) stored at 34F (30 days) transferred to 41F (7 days). Note this option was inadvertently left out of the 2013-2017 food codes. A 2018 Issue was submitted, approved, and the FDA will make these changes to the 2017 (update) Food Code.


Generally, if a commissary is stand-alone and functions as a manufacturer and supplier of foods to its satellites, then it must comply with FSMA PC (assuming gross sales > 1 million/yr). If a commissary is part of a restaurant or grocery store and makes less than 50% of the foods sold, then it may be exempt from FSMA PC. See FDA flow chart guide below or get a copy directly from the FDA.

Note concerning USDA oversight of Restaurant commissaries creating meat products.  This is 9 CFR 303.1.  Note the requirement that the commissary staff must deliver the foods to satellites.  A third party shipper cannot be used.  If third party delivery is used the operation must be under USDA inspection.

§ 303.1 Exemptions.  (iv)(c).  For purposes of this paragraph, operations conducted at a restaurant central kitchen facility shall be considered as being conducted at a restaurant if the restaurant central kitchen prepares meat or meat food products that are ready to eat when they leave such facility (i.e., no further cooking or other preparation is needed, except that they may be reheated prior to serving if chilled during transportation), transported directly to a receiving restaurant by its own employees, without intervening transfer or storage, maintained in a safe, unadulterated condition during transportation, and served in meals or as entrees only to customers at restaurants, or through vending machines, owned or operated by the same person that owns or operates such facility, and which otherwise meets the requirements of this paragraph: Provided, That the requirements of §§ 320.1 through 320.4 of this subchapter apply to such facility. Provided further, That the exempted facility may be subject to inspection requirements under the Act for as long as the Administrator deems necessary, if the Administrator determines that the sanitary conditions or practices of the facility or the processing procedures or methods at the facility are such that any of its meat or meat food products are rendered adulterated. When the Administrator has made such determination and subjected a restaurant central kitchen facility to such inspection requirements, the operator of such facility shall be afforded an opportunity to dispute the Administrator’s determination in a hearing pursuant to rules of practice which will be adopted for this proceeding.